The present invention relates to unitizing stacks of tires. Conventionally, tires are packaged for transport by stacking them coaxially and banding them with four straps. As shown in FIG. 1, each strap runs axially along the outside of the stack of tires, across the sidewall of one end tire, up through the aligned center hole of the tires, and across the sidewall of the other end tire. If the straps are insufficiently tightened, the tires are not held together securely. Conversely, if the straps are tightened to hold the stack of tires together securely, the tires are damaged because the bead of the tires becomes creased and fails to form a tight seal when mounted on a tire rim. Tires held together with straps scuff and get dirty, especially on the sidewalls located at the end of each stack. The straps hang up on forklift trucks used to transport these stacks of tires and create disposal problems after removal from the tires.
People have attempted to unitize stacks of tires by axially compressing the stack and stretch wrapping it with a web of stretch film. An example of a stretch wrapping process and apparatus is shown in U.S. Pat. No. 4,735,033, which is incorporated herein by reference. Previous attempts at stretch wrapping a stack of tires were unsatisfactory because the tires would uncontrollably collapse when the stack was compressed, or the tires would become dislodged from the wrapped stack when the stack was jolted or positioned on its side to form a horizontal array.
Accordingly, it is object of the present invention to provide a method and apparatus for unitizing load of tires which would hold the stack of tires together securely without damaging the tires.
It is also an object of the present invention to provide a method and apparatus for unitizing a stack of tires in which the tires would be prevented from being scuffed and getting dirty during transport.
It is another object of the present invention to provide a method and apparatus for unitizing a stack of tires in which the packaging would not interfere with transporting the stack of tires on a forklift or create problems of disposal.
It is an additional object of the present invention to provide a method and apparatus for unitizing a stack of tires in which a stack of tires could be transported in a manner in which they occupy the least amount of volume during transport without being damaged.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.